Zuckerberg's views on this issue are no secret. He's given $100 million to the Newark, N.J., school system to improve education there. And he's backed a controversial lobbying group, FWD.us, which wants to reform immigration law so that companies can recruit foreign engineers and tech workers more easily.

But yesterday, Zuckerberg again hinted that he thinks America is broken when it comes to educating people to take the science, technical, engineering and math (STEM) jobs that he's creating.

Zuckerberg was asked by Rory Maher of Hillside Partners whether he was having difficulty recruiting talent. The context here is that a bunch of talent — including ad products director Gokul Rajaram — have left Facebook recently for other companies. More broadly, Facebook has nearly 5,000 employees, and is growing every quarter. Facebook needs new engineers and developers in the hundreds.

Zuckerberg replied:

Yeah, I can take this. Hiring great people especially engineers is one of the biggest challenges that any technology company has. We're doing really well against the hiring goals that we have. But I mean there was a systemic issue where our country doesn't produce the volume of engineers that the companies would want to hire. And I think that that's a lot of what you hear these companies talking about. We're doing really well competitively right now. We have a really strong program on colleges where we can continue to attract a lot of best people who are graduating. We do really well at hiring senior engineers from across the valley as well. But it's just something that we invest a huge amount of time and it's really important.

The key words there are "our country." It's not just a competitive issue, he's saying, in which salary demands are going up because the tech biz is hot right now. It's that America itself doesn't have enough qualified engineers in it right now to feed the demand.